In 1991, I headed a United Nations Development Programme (UNDP) mission of Latin American physicians to evaluate a national Cuban project involving the use of interferon to treat inoperable lung cancer. At the time, there was a rumor that Fidel Castro had lung cancer was particularly interested in the research about it. Castro showed his interest, in part, when he came to visit us and discussed the findings. At the time, interferon didn’t seem to have a significant effect, but Cuban doctors persisted in their search and, even with limited resources, they have now developed a new treatment for lung cancer that shows promising results.
In September of 2011, the Chinese press agency Xinhua reported that Cuban doctors had produced the first therapeutic vaccine for lung cancer called CIMAvax-EGF. It was the result of a 25-year research project at Havana’s Center for Molecular Immunology. Although the vaccine doesn’t prevent lung cancer from developing in new patients, it turns later-stage lung cancer, specifically non-small-cell lung carcinoma (NSCLC) into a controllable chronic disease.
The vaccine contains a protein called epidermal growth factor (EGF). This substance stimulates the growth of normal cells. However, when present in excess in tumors, it causes them to multiply and grow without control. The Cuban doctors’ original approach was to pair EGF and a protein from the meningitis bacteria. When they enter the bloodstream of patients, this protein encourages their immune system to produce antibodies against the combined molecule, thus suppressing the effects of excessive EGF in the tumor cells. As a result, the vaccine doesn’t eliminate the tumors but prevents them from growing and spreading to other parts of the body.
The vaccine is given to people who already have lung cancer and where the traditional treatments have proven to be ineffective. For these types of patients, the vaccine could be a life saver. Unlike other immunotherapies, this technique uses the patients’ own antibodies, rather than using manufactured ones, thus having less side effects and being much cheaper to produce.
The vaccine, which is now available in Cuba, Colombia, Bosnia and Herzegovina, Peru and Paraguay, is relatively cheap to produce and store, and produces only very mild side effects such as nausea, chills, fever, and lack of energy. There are now agreements to test it in the United States, Japan, and some European countries.
Initial trials have shown a trend towards longer survival among vaccinated test subjects. Also, a direct correlation has been found between the level of antibodies that a vaccinated patient has produced against EGF and survival. Other trials have shown that those under 60 benefit the most in terms of survival. However, researchers caution that some early positive results to date have been found in relatively few cancer patients who were carefully selected and given special oncology care. They may not represent all the patients who could benefit from this vaccine.
Trials are currently being planned in the United States, Japan, the European Union and Serbia. In late October 2016, the United States Food and Drug Administration (FDA) authorized the Roswell Park Comprehensive Cancer Center in Buffalo, New York, to conduct a Phase I/II clinical trial of CIMAvax in patients with non-small cell lung cancer. “The chance to evaluate a vaccine like this is a very exciting prospect,” declared Candace Johnson, President and CEO of Roswell Park.
The same epidermal growth factor (EGF) acting on the lungs could play a role also on prostate, breast, colon and pancreatic cancer, thus opening a vast array of practical applications. Kelvin Lee, an immunologist at Roswell Park Comprehensive Cancer Center indicated that all these organs could be potential targets for this vaccine.
During several trips to Cuba on UN public health-related missions, I have had the opportunity to work with several Cuban physicians and became aware of their high commitment to public health. As Dr. Kelvin Lee has said, “The wonderful thing about working with our Cuban colleagues is that they really believe, in their heart of hearts, that medical care is a human right.”
The collaboration between the Cuban doctors and those at the Roswell Cancer Center is a promising one. But there are still several hurdles to overcome in large part because of the U.S. embargo on Cuba. Researchers at the Roswell Park Comprehensive Cancer Center had to wait four years to obtain the government approval for clinical trials of the CIMAvax vaccine. Clearing the path to an effective collaboration may result in one of the most important advances to combat cancer in our time.